# This file is Copyright 2020 Volatility Foundation and licensed under the Volatility Software License 1.0
# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
#

import logging
from typing import List

from volatility.framework import interfaces, renderers, exceptions, constants, contexts
from volatility.framework.configuration import requirements
from volatility.framework.interfaces import plugins
from volatility.framework.objects import utility
from volatility.framework.renderers import format_hints
from volatility.plugins.linux import lsmod

vollog = logging.getLogger(__name__)


class Check_modules(plugins.PluginInterface):
    """Compares module list to sysfs info, if available"""

    _required_framework_version = (2, 0, 0)

    @classmethod
    def get_requirements(cls) -> List[interfaces.configuration.RequirementInterface]:
        return [
            requirements.TranslationLayerRequirement(name = 'primary',
                                                     description = 'Memory layer for the kernel',
                                                     architectures = ["Intel32", "Intel64"]),
            requirements.SymbolTableRequirement(name = "vmlinux", description = "Linux kernel symbols"),
            requirements.PluginRequirement(name = 'lsmod', plugin = lsmod.Lsmod, version = (1, 0, 0))
        ]

    def get_kset_modules(self, vmlinux):

        try:
            module_kset = vmlinux.object_from_symbol("module_kset")
        except exceptions.SymbolError:
            module_kset = None

        if not module_kset:
            raise TypeError(
                "This plugin requires the module_kset structure. This structure is not present in the supplied symbol table. This means you are either analyzing an unsupported kernel version or that your symbol table is corrupt."
            )

        ret = {}

        kobj_off = self.context.symbol_space.get_type(self.config['vmlinux'] + constants.BANG +
                                                      'module_kobject').relative_child_offset('kobj')

        for kobj in module_kset.list.to_list(vmlinux.name + constants.BANG + "kobject", "entry"):

            mod_kobj = vmlinux.object(object_type = "module_kobject", offset = kobj.vol.offset - kobj_off)

            mod = mod_kobj.mod

            name = utility.pointer_to_string(kobj.name, 32)
            if kobj.name and kobj.reference_count() > 2:
                ret[name] = mod

        return ret

    def _generator(self):
        vmlinux = contexts.Module(self.context, self.config['vmlinux'], self.config['primary'], 0)

        kset_modules = self.get_kset_modules(vmlinux)

        lsmod_modules = set(
            str(utility.array_to_string(modules.name))
            for modules in lsmod.Lsmod.list_modules(self.context, self.config['primary'], self.config['vmlinux']))

        for mod_name in set(kset_modules.keys()).difference(lsmod_modules):
            yield (0, (format_hints.Hex(kset_modules[mod_name]), str(mod_name)))

    def run(self):
        return renderers.TreeGrid([("Module Address", format_hints.Hex), ("Module Name", str)], self._generator())